Question

Which of the following processes is not responsible for the presence of electric charge on the sol particles?
A. Electron capture by sol particles
B. Adsorption of ionic species from solution
C. Formation of Helmholtz electrical double layer
D. Absorption of ionic species from solution

Answer 1

Hint: First we need to have basic understating of colloidal particles and colloidal properties. When we talk about colloidal solutions we know that they are quite stable but are invisible to the naked eyes.

Complete step by step answer: Now, let’s understand what a colloidal solution is. A colloidal solution is a heterogeneous mixture that consists of particles that are in a dispersed phase and a dispersed medium.

After understanding the basics of a colloidal solution we need to know the origin of electric charge on colloidal particles to solve the above question.

- First is the frictional electrification which occurs due to the rubbing of colloidal particles and molecules of any dispersion medium. Then, the particles get charged.

- Next, is electron capture in which the particles from the atmosphere and during electro dispersion the Bredig's arc get charged.

- Then, we have studied adsorption of ions from solutions. As we know that ions have the same lattice structure that can be adsorbed by ionic colloids.

- After that there is dissociation of molecules which is followed by aggregation of ions. Here, we can consider the example of a soap that belongs to $RCOO - $ group is dissociated in the form of $N{a^ + }$ ions that forms clusters with negative charge.

Lastly, we know that dissociation of the electrolytes get adsorbed on the surface of a colloidal particle during precipitation.

So, after referring to all these properties of electric charge on a colloidal particle it is evident that the answer to this question would be option D.
i.e. absorption of ionic species from solution. As there is no absorption so it is not responsible for electric charge present on the solution particles.

Note: We must know that a sol is a type of colloid in which solid particles are suspended in a liquid. Therefore, the particles in a sol are very small. And the colloidal solution shows the Tyndall effect and is stable. We can prepare Sols by condensation or dispersion.